Ironbark, I have three starter nuts same size here if they are any use to you? The thread is only about a quarter inch by the looks, but I measured them and there would definitely be room to drill out the hole bigger and then thread them with your 1/2" BSF tap. They would then be pretty much identical to the original Victa ones. I had considered taking them to an engineering place to get them precision drilled and threaded, but all the places around here have a minimum charge of $100 on any work they undertake. Far too expensive.
